1. Field of the Invention
The present invention relates to a service handover. More particularly, the present invention relates to an end-to-end service handover control apparatus which controls an end-to-end service handover between terminals using information associated with the terminals which operate based on an Internet Protocol multimedia subsystem (IMS), and a method using the apparatus.
2. Description of Related Art
A function of an Internet Protocol multimedia subsystem (IMS) is to provide a new service in Internet Protocol (IP) based wireless access network environments. The IP based wireless access network environments may include a wireless LAN (WLAN), a wireless broadband (WiBro), a world interoperability for microwave access (WiMax), and a wideband code division multiple access (WCDMA).
Terminals, which are operating on an IMS based network, are equipped with various network interfaces capable of connecting to various wireless access networks to smoothly operate in various access network environments.
When either a speech telecommunication or a video telecommunication is performed between terminals which are operating on an IMS based network, each of the terminals performs the telecommunication via a network interface capable of connecting to the each of the terminals.
Each of the terminals continuously performs telecommunications via a handover to another wireless access network environment when each of the terminals moves to the other wireless access network environment while performing telecommunications.
However, in a conventional handover, a handover prevents a cutting-off of a call which is being performed, but the handover cannot provide an end-to-end service handover to improve a call quality between the terminals.
When a user of a transmitting terminal requests a video telecommunication, and when a receiving terminal is not located in a wireless access network environment capable of performing the video telecommunication, only a speech telecommunication is performed.
While the speech telecommunication is being performed, even when the receiving terminal performs a handover, that is, even when the receiving terminal moves to another wireless access network environment capable of performing the video telecommunication, the video telecommunication can not be performed in the conventional handover.
In other words, the initially connected telecommunication is limited to speech since the terminal cannot acquire information about other terminals even when it is possible to perform the video telecommunication.
Also, when a call is performed between a terminal located in a wireless access network whose bandwidth is comparatively large and a terminal located in a wireless access network whose bandwidth is comparatively small, the terminal located in the wireless access network whose bandwidth is comparatively large unnecessarily wastes resources.
Accordingly, there is a need for an apparatus which can provide an end-to-end service handover based on information about another terminal.